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Hey all - so, as I work around my 2302's 327 to update parts, I've come to the oil pump, which I'm assuming has never been off the car. My oil pressure is right at 40 when cruising, and it goes right back when I start moving again. No fluctuation, engine is smooth and quiet. Had the pan down two weeks out, cleaned it and the pickup screen. My concern is that the pressure really drops when it's hot. I don't have an external gauge hooked up, so I can't say for certain, but it's got to be around 5 psi at hot idle, and it does tick somewhat at that point. I know the pressure dropping when it's hot is completely normal, but it does seem like there's probably some wear between the pump and increased "main and connecting rod bearing clearances." I can't do anything about the bearings at the moment, but I figured the pump would be fairly manageable maintenance item. I was hoping to acquire a rebuild kit, clean, update the internals and carry on. But I've definitely hit a snag.

I know folks will ask - I'm running 7 qts. of Lucas Oil 10w-40 Conventional Motor Oil. I've also had the head off, removed and cleaned all the hydraulic lifters (replaced a couple excessively noisy ones). I haven't removed the oil spring and regulator to inspect the piston and check for dirt per a suggestion in the manual - is this a rabbit hole worth going down (I assume the pump can stay on the car to do this)?

I first tried Kanter who has the rebuild kit listed as backordered with no indication as to if/when kits will be stocked again. Merritt says they don't carry the rebuild kits anymore. I tried Egge Machine, who mentions a rebuild kit and/or service on their website, but connecting with them, they said they just source the kit from Kanter and can't rebuild them without the kit. So I feel like I'm in a silly obsolescent loop. Are there any other sources for kits or rebuild services I'm missing? Or is a rebuild likely to make any appreciable difference? (I spoke Dwight Heinmuller briefly - he's been an amazing source of insights, and of course, parts help - he suggested the pumps are generally pretty bulletproof, so maybe it is just dirty?)

Thanks in advance for any thoughts on this!

The chances of your pump actually needing a rebuild are very small. The cover gaskets that came with engine gasket sets for many years were too thick and reduced oil pressure by causing too much end play. The oil would run around the gap between the gears and the body. I have made big improvements on some cars by cutting a new gasket out of a piece of ordinary notebook paper, just a little less than .002 thick. The whole job can be accomplished in about 40 minutes, and you for sure don't want to take the pump out of the block, just take the cover off.

If you are still having problems then consider a 10 PSI check valve placed in front of the oil filter.

Here is a related thread btwhttps://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=26476&post_id=253349

Awesome, I know what I'm doing when I get home today!

I did this:


Parker Brass Check Valve C400BV-10P 5GPM 2000PSI

placed in front of the oil filter (between the oil filter and the "tee").

So at idle, if the pressure drops below 10 psi no oil flows to the filter it all goes to the lifters.

As a quick curiosity... cap came off no problem). Found some sludge build up, so I took the pressure relief valve cap off. I was surprised to find two stacked lock washers inside the cap between the spring and the seat inside the cap. Not seeing any lock washers in the cap in the diagram - guessing they're not supposed to be there.

Guessing I have the wrong spring, and the lock washers were added to sort of lengthen the spring to approximate the original? Or Should I try to locate another spring? Just seems odd...

Also for verification - is this about what the gasket should look like?

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People sometimes add a spacer to the spring, it puts the peak pressure at > 35 psi (40 in your case), but reduces the slight bit of bypass at lower pressures from what I understand, so it gives you a slightly higher pressure at idle.

Ross would say that it's not a oil pressure problem that you are dealing with, but worn lifters. That's what worn lifters do, they tick at hot idle, because at idle is the longest time they have to hold pressure, since the engine is turning slowest. That was the problem in my case. All of these cars have pretty low oil pressure at hot idle, there was even a service bulletin/owners manual notice that indicated that the oil light may flicker at hot idle. Ross would say that, as long as there is oil there at all, the lifters should work, since they actually pump themselves up, they have a piston and a check valve, they suck oil from the oil gallery, not really get oil pumped into them. So as long as the oil galleries are full (oil pressure > 0) the lifters should work if they are not worn.

Good point Jerome.

Joe if you have hydraulic lifters then you should test them.

But I think your engine would have mechanical, so they may need adjusted. A typical 5–10k mile service item.

Video here by Ross

Thanks, guys! My 327 does indeed have hydraulic lifters. I had them all out when I did the head gasket and valve job a couple months ago. Two of the lifters came out and were replaced with NOS. I determined the bad lifters with a stethoscope. I've seen Ross's video on testing the hydraulic lifters. I'll need to recreate that jig! It definitely used to be much worse and (thankfully) not the primary concern for me at the moment. I'll probably do the valve guides at some point next summer, at which point I'll dig back into the lifters. Just need that excuse to take the head off again. Meanwhile, if I can eek out a little more oil pressure with some of these ideas, I'll call thay a win!